Rails isn't slow.
Your architecture is.
Shopify, GitHub, and Basecamp run on Rails at massive scale. If your app is crawling, it's not the framework's fault—it's technical debt.
The "Rewrite" Trap
When Rails apps get slow, teams panic. They assume they've "outgrown" Rails and start planning a rewrite in Go, Node, or Rust.
This is almost always a mistake. A rewrite will cost you 12-18 months of feature freeze, and you'll likely rebuild the same performance bugs in a new language.
Rewrite vs. Optimize
The Usual Suspects
The N+1 Nightmare
Loading 1,000 records means firing 1,001 SQL queries. Identify these with tools like `bullet` and fix them with eager loading.
Memory Bloat
Loading entire ActiveRecord objects just to display a count or checking existence. This triggers the Garbage Collector, pausing your entire app.
Missing Indexes
As your `users` table grows from 10k to 1M rows, simple queries turn into full table scans.